Include graphics objects with hidden handles in axes limit calculation (bug #63095). * libinterp/corefcn/graphics.cc (get_children_limits): Get handles to all axes children including those with hidden handle visibility. Add BIST. * libinterp/corefcn/graphics.in.h (text::update_position): Do not automatically change "zliminclude" property. Axes labels are implemented as text objects, and we don't want their extent to be included in the axis limit calculation.

Copyright notices are intentionally omitted from the files in the
examples directory.  We don't want copyright notices cluttering the
manual.